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AIXpert Blog

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AIXpert Blog is about the AIX operating system from IBM running on POWER based machines called Power Systems and software related to it like PowerVM for virtualisation, PowerVC for Deploying VM's and PowerSC for security plus performance monitoring and nmon

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The title should read "Local, Near & Far ..." - I will not correct it or links might fail. With a shared processor virtual machine (I am calling this "VM" but was called LPAR!) there are various suggestions of setting Entitlement ("Desired processing units" on the LPAR profile on the HMC, I am calling this "E") and Virtual Processor numbers (I am calling this "VP"). For Capped, the Entitlement is the maximum guaranteed CPU time that you can't go over and you round up the Entitlement to the... [More]

This is a follow on to a previous blog on " PowerVM Virtual Ethernet Speed is often confused with VIOS, SEA IVE/HEA speed "- here is a Direct Link I regularly get asked : "I have just heard about this [PowerVM virtual switch | vSwitch | Hypervisor Ethernet Switch] is available but I can't find out any information at all, help!" They are wanting to run two (or more) virtual switches within the one Power machine to completely separate the network packets of groups of virtual machines (LPARs) so they know for sure there can... [More]

Update in 2016: Please note this blog is from 2011 during the initial POWER7 days and technology has moved on with faster CPUs and memory in addition there has been software improvements. I am amazed how many good computer people read this and assume this blog is true to all time! Virtual Ethernet is faster now but there is also a warning here. Here is an analogy. Most vehicles can do 10 MPH (including me on a bike), most cars can do 100 MPH (including my family car) but very few vehicles can do 1000 MPH. That last times ten multiplier is... [More]

This mysterious AIX CPU Folding area is often misunderstood, so below is what I know from osmosis from talking to various guru level developers over the last 10 years. Shared Processor virtual machines (LPARs for the old fashioned) have a setting called Virtual Processors (or VP for short). This is the number of physical CPUs that the virtual machines can spread out across - in fact, I prefer to call it the "spreading factor" as it is much more obvious what it means. This can be the upper threshold for the number of CPUs that can be... [More]

I often get asked: How large to make a pair of Virtual I/O Server (VIOS)? The classic consultant answer is "it depends on what you are doing with Disk & Network I/O" is not very useful to the practical guy that has to size a machine including the VIOS nor the person defining the VIOS partition to install it! Added new guidance at the bottom in RED Observations : The VIOS server unfairly gets a bad press but note: Physical adapters are now in the VIOS, so device driver CPU cycles (normally hidden and roughly half of the OS CPU... [More]

While I was installing a re-purposed POWER6 machine over the weekend, got round to installing my Dual Virtual I/O Servers, from DVD and then upgrading from there and I noticed a new service pack 2 for the latest VIOS version. It must have sneaked out without me noticing and there is a Interim fix too. The VIOS 2.2.0.12-FP24 SP2 Readme highlights lots of fixes including some for the Shared Storage Pool feature. A feature that I have been using and talking about (see this blog for more information). This got me thinking! I talk to lots... [More]

We have all probably seen or used the topas CEC on-screen view (topas -C command). This is started while logged into one AIX Virtual Server (LPAR) and shows all the other AIX or VIOS (as it is based on AIX) Virtual Servers of a single Power Server. Here is a reminder - this is on-line, on-screen and updated every 10 seconds or so: Here my Virtual Servers are called purple<something> and below the top machine summary we have a line for each Virtual Server and stats like AIX release, memory use, CPU stats (PhysB is the Physical CPU time... [More]

LPAR2RRD Briefly, Based on the same HMC data that Systems Director gathers is LPAR2RRD but it saves the data in the famous and excellent rrdtool database and graphing tools. This is a supported by the developer which is Pavel Hampl, IBM Czech republic, as a personal project tool and does a very good job. For more details and a sample website to look round see - AIX Wiki page for LPAR2RRD I note this is a sourceforge.net project now - See the above for a link to the project and code Cut from that AIX wiki page for the project here (all... [More]

I get email a few times a week like "Nigel, what do you recommend for getting a good view of what the whole Power Server is doing, what resources are free for reuse for further Virtual Machines and which Virtual Machines are busy" My detailed thoughts are on the DeveloperWorks AIX wiki here: AIX Other Performance Tools but it appears no one reads websites any more, so I thought I would blog a few examples by screen capture to illuminate what is available. My first Whole Power Server and Virtual Server view recommendation is Systems... [More]

I am not making a claim to fame (OK, I am really) but the UK Power Systems Advanced Technical Support group (that is me and Gareth) dropped the term "LPAR" or Logical Partition as a New Years resolution. We like to occasionally test to see if we can influence other IBMers and the IT Industry. We now in 2011 onwards use the terms: Virtual Server - this is the term used by Systems Director for over three years. While I can live with that name but the abbreviation of VS - it just does not feel or sound right. Virtual Machine - this... [More]